A collector for the primary pipes of an exhaust manifold of an internal combustion engine is known from French Patent No. 2,378,178.
It is common practice to connect the exhaust ports of a multi-cylinder internal combustion engine of light vehicles to a single exhaust system. This occurs by use of an exhaust manifold which is a single unit fitted to the face of the cylinder head comprising the exhaust ports. The exhaust manifold is normally a casting having a plurality of primary exhaust pipes each feeding into a connection point, for example through a grouping device which first groups together pairs of primary pipes. The grouping device then leads, by means of a single pipe, to a further grouping device and then into the exhaust pipe, possibly through a turbocharger. Such grouping devices are normally manufactured as castings.
These types of arrangements, particularly on five-cylinder engines, have proven to be difficult to design in a compact manner, unless pipe paths with reduced efficiency are adopted. Additionally, a further problem which is encountered when trying to group all of the primary pipes in a compact fashion is that of protecting each of the exhaust ports of the engine against compression waves from neighboring exhaust ports. This problem is worsened when the primary pipes have to be short, which would typically be the case for example when a turbocharger is fitted, or when a catalytic converter has to be located relatively close to the engine.
An object of the present invention is thus to provide a solution to the aforementioned problems such that a space-saving and yet efficient device can be achieved. In particular, the solution should be one which does not reduce performance characteristics of an engine to which the collector of the invention is fitted, and should even provide increased performance.